U.S. patent application number 10/499013 was filed with the patent office on 2006-08-10 for braking system for a trailer vehicle.
Invention is credited to Denis Battistella, Martin Mederer.
Application Number | 20060175894 10/499013 |
Document ID | / |
Family ID | 11459347 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060175894 |
Kind Code |
A1 |
Battistella; Denis ; et
al. |
August 10, 2006 |
Braking system for a trailer vehicle
Abstract
The system comprises an electro-pneumatic system (100) which
includes: first and second relay valves (104, 105) disposed between
a pressure supply inlet (1-1) and first and second outputs (21, 22)
respectively, and having respective control inputs (104b, 105b);
first and second solenoid-operated on/off valves (106, 107) each
operable in a first or a second condition respectively to allow or
prevent connection of the control input (104b, 105b) of the first
or second relay valve (104, 105) respectively to a pneumatic duct
(108), a first solenoid-operated commutation valve (109) having
respective first and second conditions in which it connects the
pneumatic duct (108) to the control input (4) of the system (100)
to receive a braking control pressure or, respectively, to an
inlet/outlet aperture (110a) of a second solenoid-operated
switching valve (110); this second solenoid-operated switching
valve (110) having respective first and second conditions in which
its inlet/outlet aperture (110a) is connected respectively either
to a discharge passage (3) opening to the outside environment or to
the said supply inlet (1.1); and an electronic control unit (ECU)
arranged to control the said solenoid valves (106, 107, 109, 110)
in accordance with predetermined modes of operation.
Inventors: |
Battistella; Denis; (Paderno
Dugnano, IT) ; Mederer; Martin; (Munchen,
DE) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Family ID: |
11459347 |
Appl. No.: |
10/499013 |
Filed: |
December 18, 2002 |
PCT Filed: |
December 18, 2002 |
PCT NO: |
PCT/EP02/14471 |
371 Date: |
July 28, 2005 |
Current U.S.
Class: |
303/7 ; 303/123;
303/127 |
Current CPC
Class: |
B60T 13/683 20130101;
B60T 8/327 20130101; B60T 8/1708 20130101 |
Class at
Publication: |
303/007 ;
303/123; 303/127 |
International
Class: |
B60T 13/00 20060101
B60T013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2001 |
IT |
TO2001A001201 |
Claims
1. A braking system for a trailer vehicle which comprises an
electro-pneumatic braking system (100) having a control input (4)
for a control pressure the value of which is indicative of a
desired braking pressure to be applied to braking elements of the
vehicle, a supply inlet (1-1) for connection to a pressure source
(103) of the vehicle, first and second outputs (21, 22)
respectively for connection to the braking elements associated with
the left and right side respectively of the vehicle, first and
second relay valves (104, 105) disposed between the said supply
inlet (1-1) and the said first and second outputs (21, 22)
respectively, and having respective control inputs (104b, 105b);
first and second solenoid-operated on/off valves (106, 107)
associated with the first and second relay valves (104, 105)
respectively and each operable, in a first or a second condition
respectively, to allow or prevent connection of the control input
(104b, 105b) of the first or second relay valve (104, 105)
respectively to a single pneumatic duct (108), a first
solenoid-operated switching valve (109) having first and second
conditions respectively in which it couples the said pneumatic duct
(108) either to the said control input (4) or to an inlet/outlet
aperture (110a) of a second solenoid-operated switching valve
(110); the said second solenoid-operated switching valve (110)
having first and second conditions respectively in which its
inlet/outlet aperture (110a) is coupled either to a discharge
passage (3) opening to the outside environment or to the said
supply inlet (1-1); and an electronic control unit (ECU) arranged
to control the said solenoid valves (106, 107, 109, 110) in
accordance with predetermined modes of operation and, in
particular, operable selectively to obtain: an increase in pressure
applied to the control input (104b), 105b) of at least one of the
said relay valves (104, 105) by controlling the said solenoid
valves (106, 107, 109, 110) so as to achieve a first operating
condition in which both solenoid-operated commutation valves (109,
110) are in the aforesaid second condition, while the
solenoid-operated on/off valve (106), associated with the relay
valve (104, 105) is in its aforesaid first condition; or a
controlled decrease in pressure applied to the control input (104b,
105b) of at least the said relay valves (104, 105) by controlling
the said solenoid valves (106, 107, 109, 110) so as to adopt a
second operating condition in which the first and second
solenoid-operated commutation valves (109, 110) are in their second
and first conditions respectively, while the solenoid-operated
on/off valve (106, 107) associated with this relay valve (104, 105)
is in its said first condition.
2. A system according to claim 1, further comprising pressure
sensor means (111-114) for supplying the said electronic control
unit (ECU) with electrical signals indicating the value of the
pressure at the control input (4), the supply inlet (1-1) and the
said first and second outputs (21, 22) of the system (100).
3. A system according to claim 2, in which additional sensor means
(115) are connected to the electronic control unit (ECU) for
supplying electrical signals indicating the load condition of the
vehicle.
Description
[0001] The present invention relates to a braking system for a
trailer vehicle.
[0002] More specifically, the invention relates to a braking system
for a trailer vehicle which comprises an electro-pneumatic system
including a pair of relay valves for applying braking pressure to
the braking elements associated with the left and right hand
respectively of the trailer, a plurality of solenoid valves,
selectively operable to control the relay valves, and an electronic
control unit for controlling the said solenoid valves in accordance
with predetermined modes of operation.
[0003] One object of the present invention is to provide a braking
system of the aforesaid type which is very simple and requires
fewer solenoid valves than prior art systems to control the relay
valves associated with the braking elements or brake actuators.
[0004] This and other objects are achieved according to the
invention by providing a braking system the main characteristics of
which are claimed in the appended Claim 1.
[0005] Further characteristics and advantages of the invention will
become apparent from the detailed description which follows,
provided purely by way of non-limitative example, with reference to
the appended drawing, which is an electro-pneumatic circuit diagram
for a system according to the invention.
[0006] In FIG. 1, a braking system for a trailer according to the
invention is generally indicated EBS.
[0007] The system EBS comprises an electro-pneumatic braking
system, generally indicated 100 and an associated electronic
control unit, indicated ECU.
[0008] In the following description of the electro-pneumatic system
100, reference numerals are mostly greater than 100, while certain
parts, and in particular certain connectors, have been given
reference numbers less than 100, corresponding to the numbers
conventionally used in the art for connectors for pneumatic brake
systems.
[0009] The electro-pneumatic system 100 is provided for
installation on a trailer vehicle and has a control input 4 for
receiving brake control pressure from a valve for controlling
braking of the trailer vehicle 101, installed in the tractor
vehicle 102 to which the trailer is attached. The pressure applied
in operation to the input 4 of the system 100 indicates the desired
braking pressure to be applied to the pneumatic braking elements of
the trailer.
[0010] The system 100 also has a pressure inlet 1-1 for connection
to a pressure source 103 provided in the trailer, such as a
pressure tank.
[0011] The system 101 also has first and second outputs 21 and 22
for connection to the pneumatic braking elements (known per se and
not shown in the drawing) associated with the wheels on the left
and right side respectively of the trailer.
[0012] The electro-pneumatic braking system 100 includes first and
second relay valves 104 and 105, having respective supply
connectors 104a and 105a both connected to the supply inlet 1-1 of
the system.
[0013] The relay valves 104 and 105 have respective control inputs
104b and 105b and respective outlets 104c and 105c connected to the
output 21 and the output 22 respectively of the electro-pneumatic
system 100.
[0014] First and second solenoid-operated on/off valves are
indicated 106 and 107 respectively in the drawing, and are
associated respectively with the first and second relay valves 104
and 105. These solenoid valves are of a one-way, two-position type
and can assume a first condition (shown in FIG. 1) in which they
can allow the control inputs 104b and 105b respectively of the
relay valves 104 and 105 to be connected to a (single) pneumatic
duct 108.
[0015] The solenoid-operated on/off valves 106 and 107 also have a
second condition or position, in which they cut off the said
control inputs 104b and 105b of the relay valves 104 and 105 from
the duct 108.
[0016] The control windings of the solenoid valves 106 and 107 are
connected to corresponding outputs of the electrical control unit
ECU.
[0017] Two solenoid-operated commutation valves are indicated 109
and 110. In the embodiment illustrated, these solenoid valves are
of a three-way, two-position type.
[0018] The solenoid valve 109 has a first position or condition
(shown in FIG. 1) in which it connects the pneumatic duct 108 with
the control input 4 of the electro-pneumatic braking system 100. It
can commute to a second condition or position in which it connects
the pneumatic duct 108 with an inlet/outlet aperture 110a of the
solenoid-operated commutation valve 110. This latter has a first
position (illustrated) in which is connects the said inlet/outlet
aperture 110a to a discharge passage 3 opening into the outside
environment. In its second position (not shown), the
solenoid-operated commutation valve 110 connects the supply inlet
1-1 with its own inlet/outlet aperture 110a and thus with the
solenoid valve 109.
[0019] The control windings of the solenoid valves 109 and 110 are
also controlled by the electronic control unit ECU.
[0020] Two electrical pressure transducers, indicated 111 and 112
are provided to emit electrical signals indicating the pressure at
the control input 4 and at the switching inlet 1-1 of the
electro-pneumatic system 100.
[0021] Additional pressure transducers 113 and 114 are associated
with the outputs 21 and 22 of this electro-pneumatic system.
[0022] Finally, a further pressure transducer 115 is provided to
emit electrical signals indicating the load condition of the
trailer. This transducer may, for example be associated with the
suspension of the trailer.
[0023] The pressure transducers 111-115 are connected to
corresponding inputs of the electronic control unit ECU.
[0024] In the embodiment illustrated, the electro-pneumatic system
100 has an additional inlet indicated 1-2. This inlet is provided
for connection to an emergency valve for normally receiving
pressure from this latter. The inlet 1-2 is connected to the output
104c of the relay valve 104 by means of a double non-return valve
116 connected to outputs 23 and 24 which are intended to be
connected to spring operated braking means (known per se and
therefore not shown) of the trailer vehicle.
[0025] In operation, with the electro-pneumatic system in the
condition shown in the drawing, brake-control pressure arriving at
the input 4 of the system 100 reaches the control inputs 104b and
105b of the relay valves 104 and 105 via the solenoid-operated
commutation valve 109 and the solenoid-operated on/off valves 106
and 107. The relay valves 104 and 105 apply a braking pressure to
the braking elements connected to the outputs 21 and 22 of the
system 100 which corresponds to the degree of pressure applied to
the control input 4 of the system.
[0026] The control unit ECU measures the pressure values signalled
by the sensors 111-115.
[0027] The unit ECU is set to cause an increase in pressure, when
necessary, to the control input of one or both of the relay valves
104 and 105.
[0028] In order to increase pressure at the control input of the
relay valve 104, for example, the unit ECU controls the solenoid
valves 106, 110 to adopt an operating condition in which both
solenoid-operated commutation valves 109 and 110 are in their
aforesaid second Positions (that is the position not illustrated in
FIG. 1), while the solenoid-operated on/off valve 106 associated
with the relay valve 104 is in the condition shown in the drawing,
and the other on/off valve 107 is in the condition in which it
disconnects the relay valve 105 from the pneumatic duct 108. In
this condition, the pressure inlet 1-1 is connected to the control
input 104b of the relay valve 104, by means of the solenoid valves
109 and 110, the pneumatic duct 108 and the solenoid valve 106.
This makes it possible to increase braking pressure to the output
21 of the electro-pneumatic system 100.
[0029] Once the desired pressure is reached at the output 21
(measured by the transducer 113), the control unit ECU controls the
on/off valve 106 to commute, disconnecting the control input 104b
of the relay valve 104 from the pressure supply inlet 1-1.
[0030] In order to control a pressure increase to both outputs 21
and 22, the unit ECU controls the solenoid valves 106-110 as
described above, except that this time the solenoid valve 107 is
also kept in the first, illustrated, position, thereby allowing the
control input 105b of the relay valve 105 also to be connected to
the pressure inlet 1-1 of the electro-pneumatic system. Once the
desired braking pressure is reached, both solenoid valves 106 and
107 are commuted.
[0031] In a manner similar to that described above, the unit ECU is
conveniently arranged to be able, when desirable or necessary, to
control a decrease in pressure applied to the control input of one
or both of the relay valves 104 and 105.
[0032] Thus, for example, if a decrease in pressure is required at
the control input 104b of the relay valve 104, the unit ECU
controls the solenoid valves 106-110 so as to adopt an operating
condition in which the solenoid valve 109 is in the second
condition described earlier (that it the one not shown in the
drawing), the solenoid valves 106 and 110 are in the condition
shown in the drawing, while the solenoid valve 107 is in the
condition which is not shown.
[0033] In this condition, the control input 104b of the relay valve
104 is in communication with the outside environment via the
solenoid valve 106, the pneumatic duct 108, the solenoid valve 109,
the inlet/outlet aperture 110a and the exhaust passage 3 of the
solenoid valve 110. Once the braking pressure 21 has dropped to the
desired value, the unit ECU causes the solenoid valve 106 to
commute.
[0034] In a similar manner to that described above, the unit ECU
can cause a controlled decrease in pressure to the control inputs
of both the relay valves 104 and 105.
[0035] The system described above is not however able to increase
pressure applied to the control input of one relay valve while
simultaneously decreasing pressure to the control input of the
other relay valve. Should such an operation be necessary, the
system described above would require the two operations to be
carried out in sequence, with the second being carried out after a
delay corresponding to the time required to complete the first.
[0036] This disadvantage is more than compensated for, however, by
the remarkable simplicity of construction of the electro-pneumatic
system 100 described above and, in particular, by the reduced
number of solenoid valves it requires, as well as by the simplicity
with which the unit ECU can control these valves.
[0037] Naturally, the principle of the invention remaining
unchanged, embodiments and manufacturing details may vary widely
from those described and illustrated purely by way of
non-limitative example, without departing thereby from the scope of
the invention, as claimed in the appended Claims.
* * * * *